Almost certainly nothing wrong with the camera or the card, as Paul says it’s usually caused by interruption of the file writing process.

The best thing to do is to reformat the card, by choosing the “format” option in the camera’s menu system, or by reformatting it in a card reader.

Many people, including myself, reformat their cards every time they download them. I haven’t had this situation occur for a very long time, and I shoot many tens of thousands of photos a year.

Richard.